Morphology of Flowering Plants, morphology, Morphology of flowering plants- Flowers

Gynoecium

Collection of all carpels: ovary, style and stigma

Androecium

Collection of all stamens: anther, filament and pollen grain

Morphology

External Structure

Primary root

The structure that is formed due to elongation of the radicle

Secondary and Tertiary root

Lateral roots coming out from the primary root

Tap Root System

Primary root and its branches example:mustard

Fibrous Root System

Primary root short lived and replaced with large number of roots arising from the base of the stem. Example: wheat

Adventitious Roots

Roots arising from the parts of the plant other than the radicle

Root Cap

Thimble-like structure that covers the root at the apex

Prop Roots

Supporting roots example: banyan tree

Stilt Roots

Supporting roots coming out of the lower nodes of the stem example : sugarcane and maize

Pneumatophores

In swampy areas, roots come of the ground and grow vertically upwards to get oxygen. Example: Rhizophora

Nodes

Region of the stem where leaves are born

Internodes

Portion between 2 nodes

Axillary Bud

Develops into a branch

Leaf Base

The structure through which the leaf is attached to the stem

Pulvinous

Swollen leaf base example: in some leguminous plants

Petiole

Helps hold the blade to light

Lamina/Leaf Blade

Green expanded part of the leaf with veins and veinlets

Venation

Arrangement of veins and veinlets in the leaf blade

Reticulate Venation

When the veins form a network

Parallel Venation

When the veins are parallel to each other

Simple leaf

When the leaf is incised/entire, the incision doesn't reach the midrib

Compound leaf

When the incisions of a lamina reach the midrib breaking it in into a number of leaflets

Pinnately compound leaf

The leaflets are present on a common axis,called rachis, representing the midrib

ex. neem

Palmately compound leaf

Leaflets are attached to a common point (i.e tip of petiole)

ex. silk cotton

Phyllotaxy

Pattern of arrangement of leaves on the stem or branch

Alternate Phyllotaxy

A single leaf arises at each node in an alternate manner. example:China rose, Mustard, Sun Flower

Opposite Phyllotaxy

A pair of leaf arise at each node and lie opposite to each other. Example:Guava

Whorled

More than 2 leaves arises at a node and form a whorl. Example: Alstonia

Inflorescence

The arrangement of flowers on the floral axis

Racemose Inflorescence

The main axis continues to grow, the flowers are borne laterally

Cymose Inflorescence

The main axis terminates in a flower

Thalamus/Receptacle

Swollen end of the stalk on which the flower is arranged

Bisexual

The flower has both Androecium and Gynoecium

Unisexual

The flower has either Androecium or Gynoecium

Actinomorphic

Radial Symmetry example: mustard, chilli

Zygomorphic

Bilateral Symmetry example: pea,bean

Asymmetric

Cannot be divide into 2 equal halves through any plane example: canna

Trimerous

Floral appendages present in multiples of 3

Tetramerous

Floral appendages present in multiples of 4

Pentamerous

Floral appendages present in multiples of 5

Bracts

Reduced leaves

Bracteate

Flowers with reduced leaves at the base of the pedicel

Ebracteate

Flowers with no reduced leaves at the base of the pedicel

Hypogynous

Gynoecium occupies the Highest position while the others lie below it, the ovary is said to be superior example: mustard, China rose, brinjal

Perigynous

The Gynoecium situated at the centre the other parts located on the rim of the thalamus, almost at the same level as that of the ovary, the ovary is said to be half-inferior. Example: plum, rose, peach

Epigynous

The margin of the thalamus grows upward enclosing the ovary completely and the other parts are situated above the ovary. The ovary is said to be inferior. Example: guava, cucumber

Gamosepalous

Sepals are united

Polysepalous

Sepals free

Gamopetalous

Petals united

Polypetalous

Petals free

Aestivation

The mode of arrangement of sepals or petals in floral bud with respect to the other members at the same level.

Valvate Aestivation

Sepals or petals in a whorl just touch one another at the margin without overlapping example: calotropis

Twisted Aestivation

Sepals or Petals overlap one another in a pattern/a particular direction example: China rose, cotton, lady's finger

Imbricate Aestivation

Sepals or Petals overlap one another in any particular direction example: cassia, Gulmohar

Vexillary Aestivation

The largest, standard, overlap the 2 lateral ones, wings, which in turn overlap the 2 anterior ones, keels

Staminode

Sterile stamen

Epipetalous

Stamens attached to petals example: brinjal

Epiphyllous

Stamens attached to the base of the receptacle (perianth) example:Lily

Polyandrous

Stamens remain free

Monoadelphous

Stamens united in one bundle example: China rose

Diadelphous

Stamens United into 2 bundles example : pea

Polyadelphous

Stamens United into 2 or more bundles example: citrus

Perianth

When the calyx and Corolla aren't distinct

Apocarpous

Carpels free example :lotus

Syncarpous

Carpels are fused example :mustard

Placentation

Arrangement of ovules in an ovary

Marginal Placentation

The ovules are present at one common margin eg:pea

Axile Placentation

Ovules are present on the central axis and the ovary is divided into 3 locules eg: China rose

Parietal Placentation

Ovules are present at the perimeter of the ovary eg: mustard

Free Central Placentation

The ovules are present at the central axis but this time the ovary isn't divided into locules eg:primrose

Basal Placentation

Single ovule attached to the base of the ovary eg: sunflower

Parthenocarpic fruit

Fruit formed with the fertilisation of the ovary

Region of Meristematic Activity

place where thin walled cells with dense protoplasm that divide repeatedly (meristems) are created.... cells mature and become specialized in function

Region of Elongation

Where cells produced by mitosis undergo a period of elongation in the direction of the axis of the root.

Region of Maturation

Root hairs are produced in the...

Assimilatory Roots

Roots modified to perform photosynthesis

Ex. Tinospora

Tendrils (Stem Modification)

Thin spirally coiled, develop from axillary bud, and help plants grow.

ex. gourds (cucumber, pumpkins, watermelon)

Thorns

Woody, straight, pointed.

Protect plants from browsing animals

ex. Citrus Bougainvillea

flattened- Opuntia

cylindrical- Euphorbia

Tendrils (Leaf Modification)

modified for climbing

ex. peas

Spines

Modified as a defense mechanism

ex. cacti

Calyx

sepals

Corolla

Petals

Endosperm

a tissue produced inside the seeds of most flowering plants around the time of fertilization.

surrounds embryo

bulky and stores food

Testa

outer layer of seed coat

Tegmen

inner layer of seed coat

Hilum

scar on seed coat through which the developing seeds were attached to the fruit

Micropyle

small pore above hilum through which pollen tube can enter

Aleurone Layer

outermost proteinaceous layer of endosperm

Scutellum

large and shield shaped cotyledon in embryo

Coleoptile

Sheath enclosing plumule

Coleorhiza

sheath enclosing radicle

phylloclade

stem performing photosynthesis

example - opuntia(flattened),

euphorbia(cylindrical)

cladode

internode modificn

pinnate

neem(rachis)

palmate

silk cotton

pulvinus

Swollen leaf base in leguminous plants

hypogynous

Mustard, china rose, brinjal

perigynous

plum

rose

peach